Code Definition

B0179 — Output air temperature sensor signal out of range - sensor 2

System: Body  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About B0179

B0179 is a generic (obd-ii standard) body diagnostic trouble code. It belongs to the B-prefix family of codes, which covers body, interior, airbag, or comfort-electronics faults.

When B0179 is stored, the module has detected a plausibility fault — the measured value is in the electrical range but is not consistent with expected operating behaviour; and a sensor-related fault — the reported value from the named sensor is out of spec.

Scanning & clearing: Body (B) codes are often stored in the body control module, airbag module, or climate module. A basic OBD-II tool usually will not read body codes — an enhanced or OEM-level scan tool is typically required.

Because B0179 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

Output Air Temperature Sensor 2 is the secondary duct thermistor used on dual-zone or multi-zone climate control systems, mounted in the second outlet duct (typically the passenger-side or rear zone) downstream of its blend door and heater core feed. The HVAC control module reads its voltage to confirm that the commanded discharge temperature is actually being delivered to that zone, and uses the value to trim blend door position and recirc strategy. DTC B0179 is set when the HVAC module sees the signal from output air temperature sensor 2 fall outside the calibrated voltage range, which usual...

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